Museums and meetings

Sorry if this is more personal, but some people might be interested!
I shall be in Washington DC from April 27th to May 1st. I hope
to see the Smithsonian and the new museum at Dulles.

Ron & Margie...are you going to be around? Do you want
to have a beer bought for you? Margie, any recommendations
about visiting the museum? (I've read a fair bit on here, but
mostly about finding the place! :-) ) How easy is it to get to
using public transport?

Any other recommendations? Any recommendations for
cheap accomodation?

Thanks!
Paul